Characterizing the Viscoelastic Properties of Hydrogel Thin Films by Bulge Test

In this work, we carried out bulge test for quantifying the viscoelastic properties of poly (vinyl alcohol) (PVA) thin films with custom-developed apparatus. A viscoelastic bulge deformation (VBD) model based on the elasticity–viscoelasticity correspondence principle and spherical cap equation is established to describe the bulge deformation of polymeric thin films. The VBD model can be used to determine the time-dependent modulus by bulge test for polymeric films. Uniaxial compressive relaxation test and PRONY series fitting method are used to define the constitutive parameters of the VBD equations. We presented two types of VBD models in frequency domain under linear loading and step loading conditions. Through inverse Laplace transformation, the proposed VBD model can effectively predict the bulge deformation of PVA hydrogel thin film. Numerical simulations are also conducted to validate the VBD model under step loading conditions. This work provides a methodology to characterize the viscoelastic properties of polymeric films by bulge test.

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Physical Characterization Of Microelectronic Polymeric Thin Films

MRS Proceedings ◽

10.1557/proc-227-167 ◽

1991 ◽

Vol 227 ◽

Cited By ~ 3

Author(s):

Stephen D. Senturia ◽

Susan C. Noe ◽

Jeffrey Y. Pan

Keyword(s):

Thin Films ◽

Residual Stress ◽

Viscoelastic Properties ◽

Index Of Refraction ◽

Physical Characterization ◽

Optical Methods ◽

Technical Problems ◽

Polymeric Thin Films ◽

Membrane Methods

ABSTRACTThe measurement of the mechanical properties and adhesion of polymeric thin films and coatings poses a number of technical problems. Elastic and viscoelastic properties, residual stress, adhesion, the effects of extended cure, and the effects of adsorbed moisture and process reagents are all critical. A particular challenge is to develop measurement methods which can be used with actual samples, preferably non-destructively. This paper examines a number of methods which have been developed to make these measurements, with emphasis on methods which are sensitive enough to look at the effects of process variation and the effects of moisture exposure. Suspended-membrane methods for measuring elastic and viscoelastic properties, residual stress, and adhesion are combined with optical methods for determining index of refraction and birefringence to yield a family of techniques for performing physical characterization. Recent results on the effects of extended cure and moisture uptake on elastic properties, residual stress, and optical properties will be presented.

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CORONA-POLED NONLINEAR POLYMERIC FILMS: IN SITU ELECTRIC FIELD MEASUREMENT, CHARACTERIZATION AND ULTRASHORT-PULSE APPLICATIONS

Journal of Nonlinear Optical Physics & Materials ◽

10.1142/s0218199192000054 ◽

1992 ◽

Vol 01 (01) ◽

pp. 73-102 ◽

Cited By ~ 26

Author(s):

A. KNOESEN ◽

N.E. MOLAU ◽

D.R. YANKELEVICH ◽

M.A. MORTAZAVI ◽

A. DIENES

Keyword(s):

Thin Films ◽

Electric Field ◽

Ultrashort Pulse ◽

Elevated Temperatures ◽

Orientational Order ◽

Ultrashort Pulses ◽

Second Order ◽

Polymeric Films ◽

Polymeric Thin Films ◽

Corona Poling

Electric poling at field intensities approaching the dielectric strength of the film is possible with corona poling. Polymeric thin films with large second-order nonlinearities can be created with this poling technique. In this paper, the corona poling of nonlinear polymeric films at elevated temperatures, processing, characterization and possible ultrashort-pulse applications are reviewed. An experimental technique is presented to measure the electric field during poling of the nonlinear polymeric film. The characterization of orientational order in corona-poled nonlinear polymeric films and the effects associated with the large electric field during poling are discussed. Poled polymeric thin films are uniquely suited for second-order nonlinear optical applications of ultrashort pulses (< 50 fsec) since minimal pulse spreading occurs. The sum-frequency ultrashort-pulse application of nonlinear polymeric thin films and limitations of the thin polymeric films are discussed. Experimental results are presented of a side-chain nonlinear polymer that is ideally suited for ultrashort-pulse applications.

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Polarized Fluorescence of Spin-coated Polymeric Thin Films

Journal of Photopolymer Science and Technology ◽

10.2494/photopolymer.2.257 ◽

2007 ◽

Vol 2 (2) ◽

pp. 257-264

Author(s):

Satoko Nishiyama ◽

Masahiro Tajima ◽

Yasuhiko Yoshida

Keyword(s):

Thin Films ◽

Polarized Fluorescence ◽

Polymeric Thin Films

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PREPARATION AND CHARACTERIZATION OF POLYVINYL ALCOHOL THIN FILMS FOR ORGANIC THIN FILM TRANSISTORS AND BIOMEDICAL APPLICATIONS

Kongunadu Research Journal ◽

10.26524/krj264 ◽

2018 ◽

Vol 5 (2) ◽

pp. 16-18

Author(s):

Chandar Shekar B ◽

Ranjit Kumar R ◽

Dinesh K.P.B ◽

Sulana Sundar C ◽

Sunnitha S ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Thin Film Transistors ◽

Gravimetric Method ◽

Dip Coating ◽

Organic Thin Film Transistors ◽

Poly Vinyl Alcohol ◽

Organic Thin Film ◽

Glass Substrates ◽

Coating Method

Thin films of poly vinyl alcohol (PVA) were prepared on pre-cleaned glass substrates by Dip Coating Method. FTIR spectrum was used to identify the functional groups present in the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA.The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The thickness of the prepared thin films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD20) and cross checked by gravimetric method. XRD spectra indicated the amorphous nature of the films.Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. The observed surface morphology indicated that these films could be used as dielectric layer in organic thin film transistors and as drug delivery system for wound healing.

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Carbon Monoxide Sensing Technologies

10.21741/9781644901212 ◽

2021 ◽

Keyword(s):

Thin Films ◽

Carbon Nanotubes ◽

Carbon Monoxide ◽

Metal Oxides ◽

Electrochemical Sensors ◽

Colorimetric Detection ◽

Infrared Sensors ◽

Polymeric Thin Films ◽

Semiconducting Metal Oxides ◽

Book Covers

The book covers the sensing and monitoring of poisonous carbon monoxide pollution in the environment. The sensors covered include semiconducting metal oxides, carbon nanotubes, conducting polymeric thin films, sensors based on colorimetric detection, non-dispersive infrared sensors, electrochemical sensors and photoacoustic detectors.

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